In the prior art, there are numerous examples of trailers capable of carrying two vehicles, especially when one of the two vehicles is a boat trailer carrying a boat. There is a lot of patent activity in the field which indicates that providing a practical trailer capable of carrying two vehicles is an important problem that needs a solution. Nevertheless, in spite of the patent activity, there is a scarcity of marketed trailers solving this problem. This is so because most of the patented trailers are overly complicated, unreliable, or too costly.
The prior art of which the applicants are aware that may be germane to the patent process are as follows:
U.S. Pat. No. 3,870,339 of Goff; PA1 U.S. Pat. No. 3,909,057 of Guthry; PA1 U.S. Pat. No. 3,970,203 of Watson, Jr.; PA1 U.S. Pat. No. 4,068,772 of Prudhomme; PA1 U.S. Pat. No. 4,188,056 of Watson; PA1 U.S. Pat. No. 4,221,420 of Vencill et al; PA1 U.S. Pat. No. 4,406,477 of McDonald; PA1 U.S. Pat. No. 4,420,165 of Goodin; PA1 U.S. Pat. No. 4,469,346 of Low; PA1 U.S. Pat. No. 4,560,316 of Daniels; PA1 U.S. Pat. No. 4,589,814 of Cates; PA1 U.S. Pat. No. 4,705,289 of Weber; PA1 French Patent No. 1,188,175; and PA1 French Patent No. 1,297,191.
Generally, the prior art the prior art trailers for carrying two vehicles have undesirable features of one sort or another. More specifically, some such trailers are of such design that they must be specially fabricated for carrying two vehicles; there is no capability of retrofitting a conventional vehicle trailer. Some such trailers require immersion of the trailer in water in order to launch a boat. Many such trailers require expensive dedicated power and motion equipment for loading and unloading the carried vehicles, thus adding to inconvenience and adding excess weight that must be hauled.
Yet more specifically, it is often desired to employ a motor home or other recreational vehicle (RV) to tow a vehicle trailer that carries another vehicle, such as a small car or pickup, and a boat trailer carrying a boat. Once the relatively large and heavy RV is parked, the relatively small and lightweight vehicle carried on the trailer can then be used for transportation in the vicinity of the RV. It is much more convenient to use the small car or pickup for towing the boat trailer or for general transportation around the RV parking site than to use the large and weighty RV for such purposes. It would be desirable to provide easily operated manual means for loading and unloading a small car or pickup and a boat trailer carrying a boat from a trailer hauled by an RV.